Posted 16 September 2012 - 08:22 PM
Yes, there are many different types of gag lights. One of my favorite "gags" is a television flicker light that simulates light falling on a face from a TV. I've seen and tried lots of methods and this one works best for me. If you observe what a real TV light looks like, you will notice that the intensity and color temperature will vary when there is a radical shot or scene change on the TV. The overall color temperature is also quite cool - 6000-7000K. I like to use a minimum of 3 fluorescent units. Kinoflo Diva 200 or 400 work nicely. The middle light is usually the "base light" that doesn't change. I normally white balance my camera to 3200K and use a daylight kino with 1/4 or 1/2 CTB gel as the base. Then, I change the color temperature (warmer and cooler) on the other two lights by using gels or changing some of the tubes. During the shot, I have two electricians randomly dimming the "non-base" Divas according to the desired pace of the TV show being simulated. It takes a little practice to get the desired effect, but I like using humans instead of flicker boxes for the organic look. Besides, kinos don't like running off flicker boxes. I don't like using tungsten lights because they aren't soft enough like a TV display. If sound isn't an issue, I often add another variation. I use a fluorescent "shop work light" and put daylight color correct tubes in it. Or sometimes I use standard cool white tubes which are warmer (4800K) and which add some green. I attach this light to a household style "hand dimmer." When the voltage is up full, the light looks fairly normal. But when you dim it slowly, it goes down in intensity and begins to flicker slightly. I only let it flicker slightly, before dimming back up again. The flicker isn't too pronounced when mixed with the base light and the other light. Using this method can be very realistic, but the dimmer creates quite a hum. The advantage of this gag is that it can be built with any number or size of units for a longer throw. It becomes more challenging if one needs to see the TV at the same time. One can get away with lights slightly off axis from the source - but not too much. I once made a custom smaller fluorescent "TV gag" unit that could hide in front of most TV's. I hard wired two 24" tubes to always remain on as my base light. Then I had a friend build me a small box with a round grip on top. Inside the box was a series of floating mercury switches. As one "rocked" the level of the box, different switches turned different flo tubes on and off. Due to the nature of fluorescent ballasts, the lights were not hard on and off - but rather they "flickered" to life. The key to a realistic effect was to move the switch box slowly with minimal flicker. This mercury switch gag could also be applied to multiple tungsten bulbs (dimmed to desired color temperature) to create a random and realistic fire effect.